The Pentagon stepped up to defend the high-level appointment of an evangelical Christian general who has described America's "war on terror" as a struggle between Judeo-Christian values and Satan.

Lieutenant General William Boykin, a veteran of the elite Delta Force, is to head the hunt for high-profile targets such as Osama Bin Laden and Mullah Omar as the deputy under secretary of defence for intelligence.

But the appointment became a source of embarrassment to the Bush administration yesterday after details emerged of the general's sermons to evangelical Christian groups depicting the "war on terror" as a religious crusade. "We in the army of God, in the house of God, kingdom of God have been raised for such a time as this," Gen Boykin told an audience last year, according to an investigation in the Los Angeles Times.

The impression of a Christian holy warrior is reinforced in other speeches quoted by the Los Angeles Times, in which Gen Boykin likens Islamist radicals to the Ku Klux Klan who do not represent the true faith.

The general delivered some of his sermons in military uniform. At one event he described a standoff with a Somali warlord in these terms: "I knew my God was bigger than his. I knew that my God was a real God, and his was an idol."

He also said the George W Bush's presidency was ordained by God. However, President Bush is unlikely to appreciate the bulk of the general's comments, which defy the administration's claims that the campaign against terrorism is not a war against Islam.

Yesterday the defence secretary, Donald Rumsfeld, said Gen Boykin was a fine soldier. Although he told reporters he had not read Gen Boykin's remarks, Mr Rumsfeld said he could not prevent military officials from making controversial statements.

Muslim groups in the US said yesterday Gen Boykin's comments go even further, reinforcing the notion in the Arab world that the Bush administration's rhetoric on terror is mere camouflage for a larger project of subduing Muslim and Arab nations.